Means and methods of neutralizing and converting thrust components



y DOAK MEANS AND METHODS OF NEUTRALIZING AND CONVERTING THRUST COMPONENTS Filed June 6, 1955 July 12, 1960 3 Sheets-Sheet l Awww rmeA/fx July l2, 1960 E. R. DoAK 2,944,395

MEANS AND METHODS OF NEUTRL'IZING AND CONVERTING THRUST COMPONENTS Filed June 6, 1955 3 Sheets-Sheet 2 7 y j!) Je fe J ./7

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July l2, 1960' E. R. DoAK MEANS AND METHODS OF NEUTRALIZINO AND OONVERTING THRusT COMPONENTS 3 Sheets-Sheet 3 Filed June 6, 1955 INVENTOR. MOA/a, 004

@ f lff arme/ws# tail pipeofa power-plant.

2,944,395 MEANS AND METHoDs or NnUrRALrzrNG AND coNvERrrNG rHRUsr COMPONENTS Edmond R; Doak, Los Angeles, Calif., assignor to Doak Aircraft Co., Inc., Torrance, Calif., a corporation of California Filed .une'6, 1955, Ser. No. 513,344 Z'Cidlltls.` (Cl. Gil-35.54)

This invention relates to means and'methodsvwhereby the thrust or exhaust generated by a jet-type engine and the like may be neutralized or convertedvintofa thrust component whichis angularly related with respect to the normal axial direction of ow of exhaust gases or thrust,

such translation being utilizable in controlling the pitch and yaw of an aircraft and in facilitating hovering or rapid deceleration.

Many types ofaircraft are now utilizing power plants which produce a high velocity exhaust, such exhaust resulting inA forwardly directed, utilizable thrust.Y Such power plants are all variationsV of an athodyd and lin.

clude a ramjet, pulsejet, turbopr'op or propjet, and the turbojet. Most of these power plants and aircraft utilizing the same are most eliicient at high speeds and problems have arisen in controlling aircraft equipped with such engines or power plants, particularly when landing or where an unbalanced condition arises due to failure of one enginerof a multi-engine aircraft. The present invention is directed toward means and methods wherebyV the `direction of the thrust generated by such power plant may be controllably varied, thereby permitting a secondary utilization of'such thrust.` Moreover, the device of the present invention may be employed in generating a variable back pressure in the exhaust 'cone or nozzle of -such engines, thereby permitting the engine to operate at effective thermal efliciency and reducing the possibility of llame-out. Y

Generally stated, the advantageous results of the presen t invention referred to in greater detail hereafterV are attained by the provision of a plurality of circumferentially spaced, radially directed ports in the walls of the tail pipelor nozzle, controllable d oor means for selectively covering and uncovering such ports, and obturating elements controllably movable into the normal lpath of the exhaust gases, such elements deflecting the gases into andthrough said? po-rts. In this manner thrust may be dissipated radially instead of axially or by only having selected ports open, the. thrust may be utilizedin controlling yew or. pitching of the aircraft. a Y

An object ofthe present invention, therefore, is to disclose and provide means for secondary utilization of the thrust normally generated by a jet-type engine.

A further object of the invention lis to disclose and provide means whereby yaw and pitch of anaircraft .mayy be controlled or modified -by secondary utilization of the thrust normallyA generated by a jet-type engine designed primarily for the production cfa forward component. f Y

These and other objects, uses, advantages and details of the present invention will become apparent from the description given'hereinafter. AIn order to facilitate uriderstanding, reference will be had' to the appended drawings, in which: Y k

Fig. leis arperspective Vview of an aircraft provided with a single, rearwardly directed exhaust ductnozzle or Patented July 12, 1&6()

vice embodying the. present invention showing theradial ports in open position.

Fig. 3 is a longitudinal section taken along the plane III-III in Fig. 2V showing the obturating elements or.

vanes in normal or open position. Flg. 4 is a longitudinal section showing the Vanes in closed position with a port open on one side and closed:

on the other side.

Fig. 5 is a transvense section looking. aft along the.

form of device, the upper portion indicating the position of the elements with the vanes open and the lower section illustrating a position with the vanes closed.

Fig. 7 is an end view of a still further modification, showing the vanesin open position.'V

Fig. 8 Vis a longitudinal Ysection taken along plane. VIIIQVIII of the modification illustrated in Fig. 7.

Fig. 9 is an end view of the arrangement illustrated in Figs. 7 and 8, showing. the vanes in closed position.

Fig. l0 is a partial section along plane X-X in Fig. 9.

For purposes ofv orientation, reference is made to Fig. 1 wherein the aircraft 1 is shown as being provided with wingsz, theprincipal or longitudinal axis (also known as the axis ofy roll or the axis of bank) being indicated at -x-kx. Although the devices and method of the pres-Y ent invention areapplicable toall types of aircraft, that illustrated is provided with ducted fan units 3 and 3T carried bythe wing'tips, such. units being rotatable about f the lateral or pitch axis y-y of the aircraft. This type No. 472,313'. The tail pipe or nozzle through which the power plant exhausts and discharges high velocity gases rearwardly along the longitudinalaxis (or one parallel thereto) is' indicated at 4. It will be notedv that this tail pipe extends beyond the body or tail` section of the aircraft 1`and is provided with a plurality of circumferentially spaced ports 5, 6 and the like.v

When in normal, forward ight, the thrust-generating elements such as the ducted fan units 3 and 3', as well as the mainpower plant, are so positioned that their thrust facilitates forward progress of the aircraft, 'the units 3 and 3' being rotated so. as to direct their thrust componentsv along anaxis substantially parallel to the longitudinal laxis. When hovering, such thrust-generatn Ving units 3 and 3' may be positionedV as shown, directing their thrustsubstantially downwardly (substantially par.- allel toV the VVvertical axis of the aircraft). obtain maximum hovering ability the rearwardly directed thrust through the .tail pipe or nozzle 4 shouldY be neu,- tralized Vand such neutralization is made possible by the presentinvention by providing selectively and controllably operable obturatin'g means which form a cone within the tail pipe r4 and direct the exhaust gases radially outwardly through the ports 5, 6 and 'the like.,

Furthermore, since the ports are provided with con,-

trollable doors for covering and `uncovering' any one or FigxZlisan external sideelevation'of "one, form of def Figs. 2te 5 inclusive, disclose one form of more'of the ports, control of yaW may be obtained by o b.- structing radial llowA in all portson Aone side, thereby o b.- taining `a side thrust orcornponent tending yto turn 'the aircraft around its verticall axis. Similarly, by blocking all of theupward facing ports, a downwardlydirected thrust is attained, causing the aircraft to pitch along theV y-y axis. VThe oppositely directed lateral ports which will balanceout. The. arrangement ,here disclosed per;- mits flexible, controllable generation'of directional 4thrust components Without'excessive back pressure o n the engine andresultant loss in vpower output. l .device adapted .fomente in .manner describe@ herding:

In order to fore. As there shown, the nozzle or xed tail pipe is provided with a plurality of radially directed, circumferentially spaced ports such as r11, 12, 13, 14. These ports are preferably elongated and may be wider adjacent the outlet end of the nozzle than at the forward end, such as 12'. These portsare preferably near lthe outlet end of the nozzle and beyond the body or tail structure of the aircraft.

Controllable means are provided for covering and uncovering said ports. Such means mayV comprise guides such as 15 and `15 adjacent such port and a door 16 slidable along such guides so as to close the port in one position and open the port in another position; Any suitable means may be used in actuating the doors. For purposes of illustration, the door 16 is shownprovided with yan actuating cylinder 17 containing an actuating piston whose rod 1S is connected to an end portion of the door 16 as at 19. `Pressure huid lines 20 and 21 connected to opposite ends of the actuating cylinder 17 lead to' valving system, source of iiuid pressure and reservoir whereby, at the control of the pilot of the aircraft, the door 16 may be caused to either cover or uncover the port 13. Similar actuating means are associated with each of the other doors covering and uncovering each of the other ports.

It may be noted that the various radially directed ports :1l-14 may be of equal size or such ports may alternate in size, the larger ports being positioned in the horizontal and vertical planes. Moreover, although ports provided with forward areas smaller than rearwardly directed areas have beenillustrated, the invention is not limited' thereto.

Y Obturating'means are provided for virtually closing the open or discharge end of the nozzle'and deflecting thrust outwardly through the various ports 11-14; In the form of device illustrated in Figs. 1-5 a centrally located vaneactuator is generally indicated at 25. lt is preferable thatV such actuator is faired or streamlined so as not to impede the normal rearward ow of the exhaust gases. Actuator may be held in its position by means of a spider having 2, 3 or 4 arms, such as the arm 26 connected to the nozzle 1d. The arms may also be streamlined and provide a housing forV pressure fluid conduits leading to the actuator.

In the form illustrated, the actuator 25 is provided with a forwardly directed, central, cylindrical, stationary portion 27 terminating in the head Z8. Slidably mounted along the central portion 27 is a hollow, cylindrical y A:member 29. The membe 29 is provided with a rear, 'inwardly directed wall 3l). The stationary portion of the' actuator may also be provided with an external cylindrical member 31. Fluid-tight connection is -made between the movable member 29, the external stationary cylindrical member 31 and the centrally disposed stationary portion 27 by means of suitable seals, O rings Aand the like, such as the one indicated at 32. The rear lface of wall 30 communicates with a chamber'33 capable 'of lbeing supplied with pressure fluid through conduit 34 and .supply line 35, whereupon the movable member 29 may be caused to slide forwardly along the central, stationary portion 27. The chamber 36 formed within the hollow movable member 219 is in communication with a port 3-7 leading to channel 38, conduit 39 and supply or relief line 40. The pressure fluid lines 35 and 40 extend into the body of the aircraft and by wellknown arrangements of valves, pumps, reservoirs and the like, the movement of the movable 'member 29 of actuator 25 maybe controlled by the pilot or flight engineer.

Adjacent the rear edge of each port there is pivotally or hingedly connected to the tail pipe' or nozzle 1li a vane such as the vane 41, the vane being of such size or contour as to virtually close the port 11 When such vane is adjacent or in contact with'the inner surface of the nozzle. Similar vanes 42;, 43, Y44Y cooperate withH their respective ports. Each vane, such as the vane 41, is connected by means of a link, such as 45, to the movable element 29 of the actuator. When the actuator is in its forward position (adjacent the head 28). the vanes close the respective radial ports and are said to be in open position, inasmuch as the exhaust lgases are unimpeded and pass axially through the-tail--pipe or nozzle. When, however, it is desired to neutralize such thrust or to employ it for the purpose of controlling yaw or pitch, then` the actuator member 29 is moved rearwardly, causing the vanes Li1-44 to extend into the path of travel of the gases,tthe movable ends of such'vanes then resting against the head 28 of the actuator and forming a virtual cone whose sides are at an obtuse angle to the gases being discharged. ln such position (termed a closed position) the gases from the jet-type engines are deflected by such vanes through ports which have been opened by their respective doors such as 416.

The various vanes 41-44 may be triangular or of'any other desired shape or conguration. It is not necessary however, that these vanes, when in closed position, completely obturate the open end of the nozzle. As a matter of fact, it has been found desirable in some instances to purposely permit some of the exhaust gases to be discharged axially and in some instances portions of the vanes, particularly those adjacent the inner walls of the nozzle 10, may be perforated. Moreover, the various links such as 45 need not be of exactlythe same length butinstead alternate links may be slightly shorter than intervening links so as to facilitate overlapping of the vanes when they are in closed position, as best seen in Fig. 5.

It may be noted at lthis time that the presence of a Vcentrally disposed, streamlined actuator such as 25 at or near the open discharge end of a tail pipe or nozzle of a jet engine appears to exert a guiding effectupon the exhaust gases. Y

rthe modification illustrated in Fig. 6 distinguishes from that shown in Figs. 2-5 in that the stationary portion of the nozzle or tail pipe 10' is provided with a cylindrical, slidable extension 50, terminating in an end ring 51, such extension being'provided with the various ports 1114. This slidableY extension 50 is shown in extended form in the top half of Fig. 6, having been moved into this position by actuating cylinder 52 operably connected as by rod 53 to the extension 50 at 54. Any other suitable means for moving 4the extension 50 may be utilized. ln this extended position the por-t 14' is closed by the vane 44', the vane 44 being hingedly connected to the ring 51 as at 55. The vane 44 is also pivotally connected to a link 45', the opposite end of the link being pivotally connected as at 56 -to the end of the stationary exhaust nozzle 10. v

By retractingrthe tubular extension 50 (as by means of a working cylinder or cylinders 52) the various vanes 4144 are caused to extend inwardly and assume the position indicated in the lower half of Fig. 6. These various vanes therefore form obtunating elements which lie in planes at an obtuse angle to the direction of flow of gases through the nozzle to deflect said gases into the ports 11'-14, thereby converting or translating the axial thrust into a later-ally dispersed thrust.

Controllable door means are provided soY as to selec- 'tively direct the thrust for the control of pitch or yaw. Such means may comprise guides and sliding doors such as the door 16 carried by the slidable extension 50, each of such doors being under the selective control of an associated door-moving means such yas the cylinder 17. Conduits supplying and relieving each of the working cylinders may Vinclude flexible hose sections toacconnnodate Vthe movement of the entire slidable assembly 50. Y

A still funther modification is illustrated in Figs. 7, 8

and 9. This modification distinguishes from the preceding forms of the invention in that it illustrates a mechanical means for actuating the obturating elements or -vanes and in the form. of such vanes.' As there shown the stationary tail pipefl'tlf is again provided with a plurality of radially directed, circumferentially spaced ports 11'v-14", near the discharge end of the nozzle 10".` Positioned within this nozzle is a spider having four xed arms 61,62, 63 and 64. 'I'hese arms are joined in an `apex which is axial with respect to the nozzle and lie at -a desired angle of, say, 120 to 150 to thev oncoming exhaust gases. Each of the arms of the spider, such as the arm 61, is, in elfect, a pair of parallel rods, each rod carrying a tubular, rotatable sleeve terminating, exteriorly of the nozzle in a pinion gear, the piniongears 65 and 65 intermeshing. One of the pinion gears of each pair, such as, the gear 65, is in engagement with a movable rack 66 provided-with inclined teeth whereby longitudinal movement ofthe rack 66 is converted into partial rotation in'opposite directions of the gears 65 and 65 vand of the tubular sleeves extending into the ductr or nozzle. that the actuating means or. rack 66 causes the vanes 67 e and 68` vto open and to close'like Wings of a butterfly.

When the vanes are in extended positionthey close or obturate the nozzle; when' the vanes 67 and 68 are collapsed such vanes lie adjacent to one another and do not impede the discharge of gases through the nozzle;v When the vanes are extended and in obturating position the high velocity gases are discharged throughjthe various radial ports. Again, as in the previous modifications, the

nozzle or tail pipev is provided with selectively movable and controllable doors arranged to open or cover the.

ports, thereby permitting 'the pilot to selectively translate axial thrust into -a lateral thrust exerted either horizontalonly, vertical in both directions, or vertical in one direc- :africanas previously noted, the obturating means do not actually seal thenormal discharge channel and obturating as Each ofthe tubular sleeves carries a vane, so

and extending beyond the body of an aircraft; at leastv four circumferentially spaced, radially directed ports in a common vtransverse plane, near the end of said nozzle and door means slidably mounted on the outer surface of said nozzle for covering and uncovering each of said ports; means carried by said nozzle for controllably and selectively actuating keach of said Adoor means; an ob- Vturating vane pivotally` mounted at its rear edge on the inner surface of said nozzle adjacent the rear edge of Veach of saidgports, said kvanes being movable from an inobturatng position closing the ports into position obturating the open end of the nozzle and deflecting thrust into said ports; and streamlined, separate, vane-actuating means centrally located within said nozzle along said longitudinal axis for pivoting said vanes between ob turating and inobturating positions.

2. The device as stated in claim 1 wherein said vane actuating means includes a stationary member fixed to the walls of said nozzle and a cylindrical member slidably mounted in an axial direction on said stationary member, linkage means pivotally connecting the forward edgeof each vane with the forward portion of tion only. The vanes may have perforation's for the purpose Yof increasing the drag component and Vsuch perforations are illustrated at 70. f

Itis to be understood that the Ivarious racks 66 maybe interconnectedV and actuated simultaneously through a sliding ring or each of said racks 66 may be provided with a separate actuator, the various actuators being vinterconnected for simultaneous operation. f-

From the above description it will be evident that the concepts herein disclosed provide controllable and 'vari-Y ably adjustable means which attain thevarious objective referred to and solve or minimize the lproblems which have been previously encountered in the handling and control of aircraft employing or producing high velocity gas jets. The neutralization and deflection of thrust, particularly in multi-engine aircraft, also greatly facilitates deceleration by normal braking means, without completely stopping engines or squirting the exhaust gases forward (where they lmay be drawn into the intake with dangerous results) orimpinge upon aircraft surfaces in an undesirable manner. j

It may also be noted that although theradial parts are preferably near the discharge end of the nozzle'or duct, the configuration of the aircraft, the number of ducts used, and other considerations may make it desirable to space the parts from the end of the'nozzle or duct, the term near the end embracing such modifications, As

saidrmovable element, and separate control means for actuating said movable member forwardly and rearwardly Von saidstationary member whereby said vanes are movable into a conical structure having an apex directed ltoward the gases being ejected through said f nozzle to deflect the gases into said ports in the obturating position.

References Cited in the file of this patent UNITED STATES PATENTS 340,237 Nagel et al Apr. 20, 1886 1,237,364 Miller Aug. 21, 1917 1,457,024 Franzen May 29, 1923 2,024,274 Campini Dec. 17, 1935 2,280,835 Lysholm Apr. 28, 1942 2,637,164 Robson et al May 5, 1953 2,681,548 Kappus June 22, 1954 2,696,709y .Oulianolf Dec. 14, 1954 2,793,494 Kadosch et al May 28, 1957 FOREIGN PATENTS 610,143 Great Britain Oct. 12, 1948 860,754 Germany Dec. 22, 1952 1,092,654 France Nov. 10, 1954 510,584 Canada Mar. 1, 1955 63,238 France --..a Mar. 30.71955 

